Left side won't run past idle. Order of operations? CB360

Cursh

Loves Stock Airboxes
Okay, so I've been struggling to get this bike over the hump for a long time. I think I'm just to close to it to see clearly. I could really go for a local wrench to bounce things off of, but all my friends are mystified by any mechanical system.


Idles fine.
Timing is spot on. (electronic charlies place set static and then with a strobe.)
Just pulled the carbs, cleaned them, and ran the jets through the ultrasonic.
New boots from Kent Ohio (whatever that place is called.)
Vacuum synched to a perfect match at idle.


Is the most likely thing that I've missed something while cleaning the carbs?


I had something in the pilot jet of one of my original carbs and had to swap in a new body (pilot jet was seized beyond unsticking). That's when I ultrasonically cleaned (HFT mumbo jumbo) with simple purple (whatever the HD simple green stuff is) all 4 sets of jets and chose the ones that looked the cleanest and took the same gauge cleaning needles without any fuss. When more than two looked good I leaned towards the ones that I could find Kehin stars stamped on.


I also thought I could check to see that the petcock isn't starving one of the carbs (switch the hoses and see if the problem jumps to the other side) and swap the plugs to see if that has anything to do with it.


It's been so long since this bike was rideable (I think I rode it in Pittsburgh in 2014) that I don't know if I remember what a good plug looks like.


Thanks for any help.


If you've read this far, there is a CJ oil pickup on eBay right now for $40 plus shipping (not mine, but It almost was. I decided it wasn't worth buying a glory part for a bike that doesn't run.)


Cheers.
 
I had the same issue with a CB360. Have your coils checked and tested, as well as the plug wire and boot for any cracking. Check your valve adjustments, turn it over by hand and check both exhaust valves and measure how far they travel. I ended up having a bad exhaust cam lobe. Wouldn’t allow it to rev up, but would idle just fine.


Sent from my iPhone using Tapatalk
 
It does sound like a carb problem, but just out of idle curiosity, if you hook up a timing light on the dead cylinder and fire up the motor, does it still flash as you rev it, or does it go out above idle.
 
Hmm. I like that question. That's a question I can answer before I have to pull the carbs. Thank you. I'll let you know.

millermatic187 said:
I had the same issue with a CB360. Have your coils checked and tested, as well as the plug wire and boot for any cracking.

The coils, plug caps, and boots are all brand new and the bike hasn't spent more than an hour outside of the garage. It won't hurt to check again, though.


millermatic187 said:
Check your valve adjustments, turn it over by hand and check both exhaust valves and measure how far they travel. I ended up having a bad exhaust cam lobe. Wouldn’t allow it to rev up, but would idle just fine.
How did you diagnose this? I had "check valves" on my list, but am not really informed enough to know what to specifically look for beyond gap/travel. The top end does have an out of balance valve ticking to it. Thanks for the help and any more you can give.
 
Ok.


Valves were spot on (triple checked them).
Ignition is the problem. No spark on the left when revving.
When I swap the coils the problem stays on the left.
the rectifier is working. Power peaks at 14.8V.


Electronic ignition is my only possible remainder, right? I may be back to points. This is my 5th electronic ignition. Three Petes (who kept swapping them with me without asking questions.) and 2nd Charlie's Place (who fought me on the swaps. no judgement either way. just sharing my experiences.)


Looking for confirmation that this confirms that the electronic ignition is malfunctioning.


Cheers.
 
Sounds like it's the ignition, but could just be a lousy ground on that side. Check that you have a solid voltage to both coils as Sonreir suggested. If voltage is down, you could wire in a relay and bring solid 12v+ to both coils.
 
Yup. Love the relay idea. I’ve got a couple relays left over from my rewire.


12.5v to both sides. Points worked really well when I swapped them in, so I’ll return the electronic points to Charlies place. (Maybe they can use the good side to fix someone else’s ignition or something.) I definitely prefer trouble shooting to a black box that is supposed to work all the time.


Thanks for all of your help. You saved me from pulling the carbs and recleaning them (which wouln’t have been a fruitful use of my efforts.)
 
The 360's run very hot at head, maybe too hot for electronic ignition to survive?
I have checked temps in the past but don't remember readings. ('up there' though, 220+F) 360's run 'hotter' than most bikes as points are mounted direct to head and not on a separate cam bearing/points housing.
Yamaha and Kawasaki have done similar on 250~450 cc bikes but both have either extra fins or larger fins which obviously lowers temp 'enough'
There isn't enough heat for oil to break down (the 'dreaded' cam bearing issue) and after oil mods the top end is reliability
I've tried slotting points cover to get more airflow but even then the 'rear' trigger fails after a few months.
I think crank trigger may be needed with a separate 'black box' to fire coils?
 
Cursh said:
The coils, plug caps, and boots are all brand new and the bike hasn't spent more than an hour outside of the garage. It won't hurt to check again, though.

I work in the auto parts business

just because it's new doesn't mean it's not bad.
 
Reading 'Car Craft' few days ago, one of the editors had 3 power steering pumps before getting one that worked. ;D
 
Back
Top Bottom